An agricultural harvester known as a “combine” is historically termed such because it combines multiple harvesting functions with a single harvesting unit, such as picking, threshing, separating, and cleaning. A combine includes a header, which removes the crop from a field, and a feeder housing which transports the crop matter to a threshing and cleaning system. The threshing and cleaning system may include a threshing rotor that rotates within a housing and performs a threshing operation on the crop material to remove the grain. The housing may include adjustable concaves with perforations for the grain to pass therethrough. Once the grain is threshed, it falls through the perforations in the concaves onto a grain pan. From the grain pan, the grain is cleaned using the cleaning system, which generally includes one or more sieve(s) and a cleaning fan. The cleaning fan blows air through the sieves to discharge chaff and other debris toward the rear of the combine. The clean grain is then transported to a grain tank onboard the combine via a clean grain auger. Material other than grain (MOG), such as straw, debris, dust, etc., from the threshing section proceeds through a residue system, which may utilize a straw chopper to process the MOG and direct it out through the rear of the combine. Typically, a combine is equipped with side doors that allow an operator to easily access the threshing and cleaning system.
A corn header generally includes a conveyor, row units, and accompanying drive architecture to power the header. The conveyor is disposed aft of the row units and it may be in the form of a conveyor belt, an auger with a tubular shaft having left and right fighting, or a combination of both. The row units generally include snouts, gathering chains, and stalk rolls. The snouts are conically shaped to pass in between the rows of corn, defining a designated passageway in between the snouts for the rows of corn to travel therein. Hence, a respective row unit may have a slot to receive a respective row of corn. This slot may be between 19-38 mm wide and approximately 152 mm long. Each row unit also includes respective gear boxes to drive the gathering chains and stalk rolls. A gathering chain generally includes chain links that form an endless chain and protuberances, such as paddles, affixed thereto for contacting the corn stalks. Typically, a gathering chain has 48 chain links and 6-8 paddles spaced about the endless chain. As the agricultural vehicle traverses the field, the corn stalks are pulled inwardly by the gathering chains and downwardly by the stalk rolls. This motion causes the ears of corn to contact the base of the header, e.g. deck plate, and thereby the ears snap off their respective stalks. The gathering chains additionally help to move crop material inwardly towards the conveyor, which transports the ears of corn to the center of the header for entry into the feeder house. The stripped corn stalks are further pinched and crushed by the stalk rolls, in order to accelerate the decomposition process of the stalks. The header may also include chopping units that have reciprocating blades located beneath the stalk rolls to chop the stalks, leaves, and MOG in order to more easily incorporate the remaining residue in subsequent tillage practices.
Conventional row units may lead to a loss of yield due to losing grain in between the paddles of the gathering chains and/or at the space between juxtaposed gathering chains. Since gathering chains may have a substantial amount of space in between respective paddles there is a high probability that dislodged, i.e. free, kernels and/or ears of corn may pass through these spaces and thereby may never be conveyed into the header. Likewise, crop material may undesirably fall through the slot in between juxtaposed gathering chains. In more detail, when the ears of corn are separated from the stalks, via forcibly contacting the deck plate, a portion of the grain on an ear of corn may become dislodged on impact. For instance, up to 6% of the weight of an ear of corn can become dislodged upon impact, which could then fall through the spaces in the gathering chain and/or the slot in between juxtaposed gathering chains instead of being conveyed into the header. Also, grain may be lost as a result of plugging of the crop material at the front of the row units. As the gathering chains rotate, the paddles may undesirably break or bend the stalks which then causes a buildup of fallen crop material at the front of the row unit. This plugging at the front of the row unit can effectively decrease the efficiency of the row unit and/or lead to a loss of yield as some crop material may fall out of the row unit or may not even enter the row unit since the passageway within the row unit has become at least partially plugged.
What is needed in the art is an improved gathering chain that can more efficiently gather and convey the crop material.